Abrasive wheel



oct, 21, 1941.. o. A. CLARK 2,259,554

ABRASIVE WHEEL Filed Dec:` 30, 1940 2 Sheets-Sheet l i vv JQ. Mayra/eFEZ ,Lw/1M v f ATTORNEYS Oct. 21, 1941. o. A. CLARK ABRASIVE WHEEL 2Sheets-Sheet 2 Filed De@2 so, 1940 www W A TTORNEYJ Patented Oct. 21,1941 NT OFFICE ABRASIVE WHEELv Oliver A. Clark, Springfield, Ohio,assigner to The Safety Grinding Wheel & Machine Company, Springiield,Ohio, a corporation of Ohio l Applieanen December so, 1940, serial No.372,260

3 Claims.

This invention relates to improvements in abrasive grinding wheels, itmore particularly relating to means 'for preventing portions of a wheelwhich has bursted from ilying outwardly by centrifugal force which wouldresult in injury to the workman.

When an abrasive wheel bursts ordinarily the cracks which occur in thewheel eXtend from the periphery of the wheel to the central bore thereofresulting in segment-like portions which unless restrained will ilyoutwardly.

The object of this invention is to provide a construction whereby if thewheel bursts the broken segments will be forcibly restrained againstoutward movement.

Another object of this invention is to provide a construction that issuch that when a wheel bursts or is broken, the holding force exertedupon the wheel hub is greater than the centrifugal force generatedwithin the wheel and the segments.

A further and more specific object of the invention is to provide aconstruction whereby the ends of the hub portion of the wheel areentirely surrounded by annular members which will form in effect athroat which is narrower than the length of the hub so as to prevent thecracked portions of the hub and those portions of the Wheel attachedthereto from flying outwardly.

In the accompanying drawings:

Fig. 1 is a vertical section of an abrasive wheel and associated parts,a portion of the wheel being broken away.

Fig. 2 is an elevation of one side of the Wheel.

Fig. 3 is an elevation of the outer face of one of the clamping collars.

Fig. 4 is a vertical section of an abrasive wheel and associated partsshowing a modication, a portion of the wheel being broken away.

Fig. 5 is an elevation of one side of the wheel shown in Fig. 4.

Fig. 6 is an elevation of the outer face of one of the clamping collarsshown in Fig. 4.

Referring to the drawings, l represents an abrasive wheel of standard orapproved construction having straight sides. The wheel is mounted upon aspindle 2 driven from any suitable source of power, being clamped to thespindle by collars 3 and 4, the collar 3 being in the present caseformed as an integral part of the spindle While the collar 4 is placedloosely upon the end of the spindle and the collars clamped to the wheelby Y the nut 5 which is screwed upon the reduced portion 2 of thespindle; the reduced portion of the spindle extending through a centralbore in the hub 6 of the wheel which isk provided with a metallic orothertype bushing 1.

Inv carrying out this improvement the wheel is so constructed so as toprovide on 4each side .thereof annular recesses lv and 8 immediatelysurrounding .the endsof the lhub 6. Each of the collars 3 and 4 isprovided with a recess 9 so as to form in eiect an annular ange on eachof the collars as indicated at 3 and 4'; these collars being of standardform readily obtainable upon the market. When the parts are assembledand clamped together these flanges 3 and 4' will enter the recess 9 andthereby overhang or enclose the ends of the hub 6. Preferably aresilient washer or gasket l0 is placed in each end of the recess, thesewashers being in the present case formed of a composition orcomparatively soft vulcanized rubber and cork so that when pressure isbrought thereon they will not only be compressed but displaced wherebythe iianges 3' and 4' will enter the recesses 9 to the extent allowed bysuch compression and displacement, the diameter of each recess beinggreater than the diameter of its corresponding washer to permit of thedisplacement of the washer when comparatively soft vulcanized rubber isused either as a part or the whole of the washer. The washers are merelyused to get a better contact for the clamping surfaces between thecollars and the Wheel so far as the construction shown in Figs. 1 to 3inclusive is concerned.

It will be seen that with this arrangement when a wheel bursts andcracks from the periphery to the metallic bushing in the bore the hubportions will be positively conned against outward movement by reason ofthe fact that the iianges of the collars overhang or enclose the ends ofthe hub and form in effect a converged throat through which the hubportions cannot pass.

In Figs. 4 to 6 inclusive there is shown a modification in which theparts corresponding to parts shown in Figs. 1 to 3 inclusive are giventhe same reference characters with the addition of a prime exponent. Inthis modification the recesses in the wheel which surround the hub areindicated at l`| and the bottom of each recess is sloped toward thecenter so as to provide a recess which is cone-shaped in cross section,the washers indicated at l2 may be cone-shaped in cross section so as toconform to the shapes of the recesses, or at washers may be employedwhich are forced by the ilanges of the collars into the cone-shapedrecess to form in eiect cone-shaped washers. These washers thus acteither alone or in conjunction with the flanges of the collars toprevent segments of a burst Wheel from flying outwardly because of theWedging action existing between the Washers and the walls of therecesses.

By forming the abrasive Wheel with straight sides no machining isrequired as is necessary with a tapered wheel and also such a form ofWheel in connection with the recesses which closely surround the hubportionof the wheel permits the use of standard clamping collars whichare readily obtainable upon the market.

Having thus described my invention, I claim:

1. In a device of the character described, an.'

abrasive Wheel provided with a bore and having straight sides, a spindleexte ridingV t' ughy a bore in said Wheel, said wheel having'bneach facethereof a recess surrounding the hub thereof, clamping collars carriedby's'ai'dfspindle to secure the Wheel to said spindle, each of; s aidrecesses being of a cone-shape in cross-section in any arc ther'eoL'aWasher located in each recess of a cone shape'in cross-section in anyarc thereof to conform tothe shape of the recess, and an annularstraight-sided ilange on each collar ad'aptn'ed` to enter thecorresponding recess of.- the Wheel Ywhen' the parts are assembled.

' In a device of the character described, an

abrasive Wheel provided with a bore and having laight Sides from bore toperiphery, a spindle extending therethrough, clamping collars carried bysaid. spindle for clamping the wheel thereto, yeach collar having acentral recess therein, an annular recess on each face of said Wheeladjacent the hub thereof, and an annular straightsided flange formed oneach collar about the recess therein, said langesbeingV adapted to entersaid recesses to embrace the ends of saidl hub, anda flexible Washer ineach recess.

OLIVER A. CLARK.

